When Neil Armstrong and Buzz Aldin stepped onto the fine, loose soil of the lunar surface 20 years ago next week, science had a number of questions to ask of the moon. Was it geologically hot, or was it cold? What was its origin? Were there any protobiological substances on its surface? What geologic differentiation had occurred in its formation? How did it differ from the earth? What were the mascons, those mysterious subsurface objects, that perturbed the orbits of lunar satellites? Now, as NASA celebrates Apollo 11 with a series of events and parties in Houston and Cape Canaveral, where does lunar science stand? Among planetary astronomers there’s a consensus that the Apollo program was a scientific success. At the same time, their theories about the moon’s origin and composition await the proof of new physical evidence—evidence that lunar scientists believe only another moon mission could acquire.
The 841 ...
